The present invention relates to cosmetic compositions suitable for use on mammalian skin. These compositions comprise a bonding agent capable of attaching a cosmetic benefit agent to mammalian skin. In particular, the bonding agent is activated, trans-structured and is linked to the cosmetic benefit agents that are then in turn linked directly or indirectly to the skin.
It is well known in the skin beauty care field that cosmetic benefit agents may be topically applied to human skin. There are a number of benefit agents that can be applied to the skin for varying purposes including moisturizers, humectants, color cosmetics, etc. There is, however, a common problem that arises in each of these areas of beauty care. The problem is the failure of the above-mentioned cosmetic benefit agents to remain substantively attached to the skin to which they are applied. That is, the benefit agents that are applied fail to xe2x80x9cstickxe2x80x9d to the skin such that a long-wear result is achieved to any noticeable extent.
The present invention seeks to solve this substantivity deficiency that is typical in topically applied products by utilizing a chemical hook based technology. The operative chemical hook of the present invention is a bonding agent that serves as a gluing mechanism between a cosmetic benefit agent of interest and one or more protein molecules that are found in the skin and/or hair. In particular, Applicants have found that activating certain molecules then allows them to serve as suitable bonding agents such that improved substantivity of various benefit agents are observed on the skin. Additionally, Applicants have found that, due to the selective reactivity of the bonding agents with the proteins in the skin, an unexpected evenness of coverage benefit is also imparted by the use of the claimed compositions. That is, undesirable caking or build-up of a benefit agent does not result since substantivity only occurs at the reactive sites between the bonding agents and proteins found in the substrate.
Without being limited by theory, the chemical hook bonding agents covalently bond to certain amino acids present in proteinaceous substrates like skin, cuticles, and hair to form a substantive attachment of the desired cosmetic benefit agent to the substrate as demonstrated by the chemical reaction that follows 
wherein AA represents functional amino acids containing amino, sulfhydryl, carboxyl, or hydroxyl groups and wherein X, L, and R are defined below.
The present invention relates to cosmetic compositions that comprise a safe and effective amount of a bonding agent comprising the following trans structure 
wherein X represents a cosmetic benefit agent, L represents an optional chemical linker between X and the remainder of the bonding agent; and R represents an activating, electron withdrawing group; and a cosmetically acceptable carrier for the bonding agent wherein the composition is administered topically to mammalian proteinaceous substrates and wherein the bonding agent reacts with a protein contained in the substrate such that the bonding agent, and thus the cosmetic benefit agent, is covalently attached to the substrate, in particular, proteins and other reactive components of the skin. The invention further relates to methods of using the compositions described above as well as various products that include the claimed compositions.